EFDA-JET-CP(03)01/27

Experimental Investigation of Dynamical Coupling between Turbulent Transport and Parallel Flows in the JET Plasma Boundary Region

The mechanisms underlying the generation of plasma flows play a crucial role to understand transport in magnetically confined plasmas. In the Scrape-Off Layer (SOL) region flows along the field line are a key element to understand impurity transport and plasma recycling. Furthermore, plasma flows are an important ingredient to access to improved confinement regimes, both in edge and core plasma transport barriers. Simulations of plasma flows have been previously investigated including the effects of diamagnetic, ExB and B x grad B drifts. Pfirsch-Schlüter flows have been proposed to explain parallel flow reversal measured in the JT-60U tokamak. In general, calculated SOL flow profiles can qualitatively reproduce the radial shape of the experimentally measured radial profile of parallel flows. However, the amplitude of measured parallel flow are significantly larger than those resulting from simulations.These findings might suggest that there is a missing ingredient in previous simulations to explain the generation of parallel flows in the plasma boundary region. This paper reports experimental evidence of parallel flows dynamically coupled to radial turbulent transport, showing that turbulence can drive parallel flows in the plasma boundary region of magnetically confined plasmas.
Name Size  
EFDC030127 1.01 Mb